CATEGORY: Best practice

Maintaining your email marketing database

Maintaining your email marketing database

Your email marketing database is like a plant. It needs to be continually fed, watered and pruned if it is to stay in good health, yet some businesses still take the approach of weeding out whatever contact data they hold and blasting an email out to all and sundry in the hope of getting a few extra enquiries. You have to change from these sorts of practices to be an effective email marketer today. Here is some best practice advice on caring for your email marketing database so that it continues to bear fruit.


The arrival of the GDPR caused some to seriously review who they were contacting and how, but many others carried on regardless armed with some vagary about Legitimate Interest. Legislative factors are always important, but in practical terms, it is technology that will kill your email marketing if your database is in poor shape. Spam filtration technologies increasingly use behavioural factors to determine who is a legitimate sender and who is spammer. None of these tools care a jot about your legal team’s position on the GDPR. If you are sending emails that hit bad addresses, old mailboxes or even good ones where the contact has no interest in your communications, you’re going to find yourself in trouble. The behavioural algorithms that protect inboxes from fraud and spam can also stop email marketing in its tracks. This applies to both B2C and B2B email marketing.


Business to business data degrades by roughly 25% per annum, so you are dealing with an ever decreasing pool of good data unless you are actively growing your list. That degraded 25% can also get you into trouble if you contine sending to it.

Services such as Mimecast and Proofpoint (formerly Cloudmark) offer increasingly stringent protection to enterprises worried about fraudulent email – they also hoover up email marketing and put it in quarantine. There is similar, if slightly less draconian software built into Microsoft Outlook on Office365 - Focused Inbox (formerly Clutter) learns what you are reading and what you’re not and puts what you are not reading out of sight. The most important aspect of how these technologies work is that whether or not your email is viewed as risky is democratised. If you’re hitting a bunch of unattended mailboxes for staff who are long gone, that tells the recipient server and the protection technology attached to it that you’re probably best off in quarantine for everyone. Even those that remain alive and well at their desks are then blocked.

Real-time blacklisting, complaints and just large volumes of non-opens lead these technologies to then report to each other and then block email at a global level, even if that means some who wanted the messages miss them as a consequence. “Check your Junk folder” has become an increasingly prevalent phrase in work environments for this reason in part.


 First off, from a legal perspective, you have to have up to date consent for B2C email marketing, but that isn’t a free pass forever. Second, consumer email marketing is a simple case of value exchange. If you are not continually giving consumer contacts things they find of interest, you will find ongoing engagement is challenging. That can be a relatively simple case of continual offers for those with a transactional relationship with their database.

There is also a presumption of guilt rather than innocence for new arrivals to a consumer inbox, so it is important that new subscribers are acknowledged and encouraged to open and click after first subscribing. In the longer term, old addresses in your data can be dangerous. Many consumer email addresses are disposable and not used regularly if at all. Apparently old Gmail accounts are now turned into spam traps after 2 years of inactivity, even if the contact opted in originally.

We offer a data healtcheck service to new and existing clients which will identify bad addresses in your data. This is great if you have a database with a few email skeletons in the closet, but this is not a panacea. It is never too early or too late to start good email database practices. 

Feeding it – new contacts = new opportunity

Watering it – segmentation = better engagement

Pruning it – suppressions = better sender reputation

Feeding it

 Make sure that your website and other systems are feeding new contacts into your email marketing database automatically. If you have gated content, this will be about generating new leads. If you have a transactional site, encourage customers to keep in touch with offers at the point of transaction. Before you get to the transaction, popups with discount codes for first orders is a tried and tested data capture methodology.


With all of the above, the key thing to ensure the new contacts that you feed your database interact with your emails soon after engagement. That presumption of guilt for new inbox arrivals will be overcome if they are looking out for the link to download your whitepaper or that coupon code for 10% off their first order. The positive human interaction with that first email tells the spam filter that your emails are wanted and helps keep them reaching the inbox.

Double opt-in

Legal duties aside, verifying email subscriptions is a great way to keep your database and deliverability healthy. Firstly, in a similar vein to the autoresponder principal, encouraging positive interaction with the email at the point of signup is ideal. The offer or the download may be compelling, but a compliance requirement may be even more compelling. Without verification, they don’t get the good stuff to follow.

The other issue is that people use disposable addresses a lot. These addresses can bloat your database with dud emails that will hurt your deliverability over time. Some B2B forms now restrict emails to only company domains (no Gmail or Hotmail), but this can discourage genuine interest from those who like to or have to keep their corporate inbox clean. The key thing is to establish a deliverable address and that is why double opt-in is so useful.

Watering it

Once you have sustainable processes for acquiring and verifying new contacts, it is then a question of keeping them up to date and leveraging maximum value from them. That probably means them getting maximum value from you too. You achieve that through relevant content, offers or whatever else it is that represents the type of relationship they want from you and that you want from them. 


The best way to deliver relevance is through segmentation and there tend to be four core categories of segmentation that work best for email marketing:


There is a reason this one is first. It is the best. Segment your contact data based on their behaviour. What they do gives you the clearest idea of what you should do. This is where things like dynamic content and remarketing come into their own. Timely and relevant communication based on tracked actions from other email campaigns and from your website.


Marketing is all about changing behaviour. The more you know about your customer, the more effective you can be at influencing them. Things like age, gender and income help you to deliver messaging tailored to specific segments of your database. 


In the same way the consumers are not all the same, neither are businesses. SMEs are likely to be looking for something different from you than enterprises will be. Likewise, the agenda of decision makers in a finance capacity will be different from their colleagues in I.T.


Many customer behaviours follow patterns based on dates. By tracking birthdays, anniversaries, renewals and purchases, you can target contacts automatically at the right time with the right message.

Segmenting your data is often best achieved by ensuring information flows automatically between your business systems. This is also true of just keeping the data accurate with or without segmentation. There is only so much you can ever hope to achieve if you’re still doing it all manually in spreadsheets.



Your central repository of contact data should be a junction box taking and feeding data to your email marketing database on a continual basis. It also offers a good way of keeping what happens in the real world in sync with what is happening digitally.


It may already be part of your CRM data, but for customer marketing, a great source of up to date data tends to be the Finance Department. It is one thing if a piece of marketing goes to the wrong contact, but quite another if your invoice does. You can usually be confident that your accounts team are sitting on a goldmine of good data as well as the money itself.

Campaign Actions

Previous interactions with emails give you a good steer as to what is working and what is not. Target contacts taking positive actions with more of the same. Target contacts not showing any action with something different.

Website Actions

For every website action, there is an equal and opposite email reaction. By tracking the pages your contacts visit, you can enrich the data you hold about them with tremendously useful business insight. Learn more about how in-leads provides a simple website tracking solution.

Preference Centre

The best source of accurate contact data are the contacts themselves. They are also the best  judges of what you should be sending them. A Preference Centre gives your contacts the ability to specify how you should communicate with them and what data you hold about them. It is also a good way of minimising unsubscribes and providing GDPR-friendly granular options of consent.

Prune it 

Once you have a process of acquiring and segmenting contacts that works on a sustainable basis, you can look to suppress data that at best will never give you business and at worst, may cause you deliverability problems.


You have a legal obligation to provide a way for contacts to opt out. Preference Centres are great for mitigating this to an extent, but if a contact wants to unsubscribe, let them do it easily. Unintuitive unsubscribes tend to lead to being marked as junk or spam which is worse from a deliverability perspective.


Most bounce handling will be done automatically by your ESP, but it is still worthe examining who is bouncing and why. Look for trends with particular bounce reasons and for particular domains. Do you have a Gmail problem or if B2B, do you have issues with a particular company.


How many emails does it take to prove that there is nobody home? Ten, twenty, fifty? We’ve seen lists with contacts that have been emailed hundreds of times without ever opening or reading a thing. If you want to see an immediate improvement in your open rate, just suppress those who have not engaged ever or in a long time. The threshold will depend on a number of factors unique to your business.


It is incredible how often current customers end up in prospecting lists for new business. Make sure your customer marketing lists are up to date too and devise ways to automatically suppress these contacts from prospecting activity. See Finance earlier in the article for a useful clue.


There are many aspects to a successful email database strategy. The important thing is to ensure the systems and processes to maintain it are implemented and adhered to. Dealing with a few bits of changed data each week is much easier than trying to tidy up a mess that has been neglected for months or years. Invest in integration and keep tabs on who is adding and changing data from a quality control perspective. Putting clients in charge of their own data is a great way of making this task less challenging for internal resources.

If you can keep things tidy, then email marketing is still incredibly cost effective way of communicating with and influencing a large contact list digitally. Social channels now limit organic reach to the point where you have to pay to play. Free access to the inbox is a still a matter of a value exchange, but one where you should see a consistently excellent ROI as long as you feed it good contacts, water it with intelligent segmentation and prune it for inactive contacts and inaccurate data.

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